1. Field of the Invention
The present invention relates to a method for producing a cordierite ceramic honeycomb structure by extrusion.
2. Description of Related Art
Cordierite ceramic honeycomb structures are used as an exhaust gas purifying catalyst carrier, a filter, or a heat exchanger for automobiles or the industrial use.
In order to improve the purifying performance and the heat exchanging efficiency, and reduce the pressure loss, a thin partition wall is adopted in the cordierite ceramic honeycomb structures.
In general, the extruding method is used for the cordierite ceramic honeycomb structure for improving the mass productivity. For the extrusion convenience, a forming auxiliary agent such as a binder and a surfactant is added in the ceramic material batch for extruding.
However, in extruding a thin cordierite ceramic honeycomb structure recently, a problem was discovered in that the unbaked clay can partially aggregate during the extrusion and thus the extrusion property and the shape stability are deteriorated, besides, the pressing area becomes smaller.
Further, if the amount of the binder or the surfactant is increased in order to solve the problems, a crack can be generated in the drying process, and the preheating member needs to be wider due to deashing during firing.